LB-65CXX-01

Features

65C02 or 65C816 CPU
2 MHz (typical) Oscillator on card
Reset switch/power monitor
Address decoder PLD drives RAM/ROM/IO chip selects
100x50mm card

Design

Memory Map

0x0000-0x7FFF - 32KB SRAM
0x8000-0x8FFF - 4KB I/O space
0x9000-0xBFFF - Free space (12 KB SRAM Using 128KB SRAM)
0xC000-0xFFFF - 16KB EPROM space

CPU

65C02 or 65C816 CPU
- 65C816 requires mods to the PCB (see Checkout notes below) or Rev 2 PCB
2 MHz
Install jumper J2:1-2 if CPU is not a WDC 65C02 or WDC 65C816

R65C02 vs W65C02 vs W65C816 CPUs

U1 Pin	U1 Pin Name	Sig Name	Pullup	R65C02 sig	W65C02 sig	W65C816 sig
1	VSS/VPB	J2 selects	N	VSS (IN)	VPB (OUT)	VPB (OUT)
3	PH1OUT/ABORT	ABORT*	REV2	PH1OUT (OUT)	PH1OUT (OUT)	ABORT (IN)
5	NC/MLB	MLB	N	NC	MLB (OUT)	MLB (OUT)
7	SYNC/VPA	VPA	N	SYNC (OUT)	SYNC (OUT)	VPA (OUT)
35	NC/E	CPUE	N	NC	NC	EM/NAT (OUT)
36	NC/BE	IORQ*	REV2	NC	BE (IN)	BE (IN)
37	PH0IN/PH2IN	CPUCLK	N	PH0IN	PH2IN	PH2IN
38	SO/MX	CPUMX	REV1/2	SO* (IN)	SOB (IN)	MX (OUT)
39	PH2OUT/VDA	VDA	N	PH2OUT (OUT)	PH2OUT (OUT)	VDA (OUT)

VDA/VPA (65C816)

VDA/VDA
- 00, Internal operation (invalid address bus)
- 01, Valid Program Address
- 10, Valid Data Address
- 11, Opcode-fetch

Chip Set

Ordered from Ebay

Picture shows 3 MHz CPU
Received 2 MHz CPU
As received:

Oscillator

PLD

ATF16V8B part
TL866ii Plus Programmer

PLD Listing

PLD File

Name       LB-65CXX-01_PLD;
Partno     ATF16V8B;
Date       09/12/24;
Revision   01;
Designer   DOUG G;
Company    LAND BOARDS LLC;
Assembly   LB65CXX01_U2;
Location   Rustbelt, US;
Device     G16V8;

/*
	65C02 Control
*/

/* Control inputs */
PIN    1   = CLK;
PIN    2   = CPUA12;
PIN    3   = CPUA13;
PIN    4   = CPUA14;
PIN    5   = CPUA15;
PIN    6   = CPUREAD;
PIN    8   = VPA;
PIN    9   = VDA;		/* Pin 39, PH2OUT - Enable line */

/* Address Decode and Chip Select outputs */
PIN    13  = !IOCS;
PIN    14  = !ROMCS;
PIN    15  = !MEMRD;
PIN    16  = !RAMCS;
PIN    18  = RDY;

RAMCS = !CPUA15 & CPUREAD		/* 0x0000-0x7FFF */
#       !CPUA15 & !CPUREAD & VDA;

IOCS = CPUA15 & !CPUA14 & CPUA13 & !CPUA12 & CPUREAD	/* 0x8000-0x8FFF */
#      CPUA15 & !CPUA14 & CPUA13 & !CPUA12 & !CPUREAD & VDA;

ROMCS = CPUA15 & CPUA14 & CPUREAD;	/* 0xC000-0xFFFF (16KB space)		*/

RDY = VDA;

MEMRD = CPUREAD;

Reset Controller

DS1813-5 Reset Controller
5V Power Monitor
Reset controller
Reset pushbutton to ground

Backplane connector

Software

LB-6502 GitHub
SIMPLE-6502 Software - Reference software

Assembly Language Development Toolchain

cc65 Assembler, Linker, Compiler
- Backup copy
Example batch file to assemble code and produce .hex file

ca65 AciaTest.s -o AciaTest.o -l
ld65 -C AciaTest.cfg AciaTest.o -o AciaTest.bin
srec_cat.exe AciaTest.bin -binary -o AciaTest.hex -Intel

AciaTest.cfg

MEMORY {
	ROM:		start = $C000, size = $3FFA, fill = yes, fillval=$FF, file = %O;
	VECTS:		start = $FFFA, size = $6, fill = yes, fillval=$FF, file = %O;
}

SEGMENTS {
	CODE:		load = ROM,	type = ro;
	VECTS:		load = VECTS,	type = ro;
}

ACIA Test Code

ACIATest.s
Loopback serial data
Works

Simple Monitor 6502

SimpleMon6502.s - GitHub repo
Contains
- ACIA init, read, write
- Simplest commands mostly for function development
- String functions
  - Read a string
  - Write a string (macro)
  - Write hex value as a string
Dump page (256-bytes) of memory

6502 Enhanced BASIC

Enhanced BASIC Source Code on GitHub
Enhanced BASIC Quirks and fixes
- Fixes the IRQ_vec missing error when assembling the code

; Ibuffs can now be anywhere in RAM, ensure that the max length is < $80,
; the input buffer must not cross a page boundary and must not overlap with
; program RAM pages!

;Ibuffs            = IRQ_vec+$14
Ibuffs            = VEC_SV+$16
                              ; start of input buffer after IRQ/NMI code
Ibuffe            = Ibuffs+$47; end of input buffer

Added some of the patches from Enhanced BASIC Quirks and fixes
- Patched code is here

Boots to request memory size

Runs on card

OSI BASIC

LB-6502 GitHub
Grant Searle's 6502 design
- Link to Grant's files
- Local copy
Source code
- osi_bas.s <== the Microsoft OSI BASIC and I/O routines SOURCE all in a single file
- Grant's I/O routines are at the end of it
Files to allow the source to be assembled on a Windows based machine
- assemble.bat <== double click to assemble osi_bas.s and link to binary file "osi_bas.bin"
- This should be exactly 16K
- osi_bas.cfg <== configuration file for the linker (ensure ORG and entries in this file match if you change any)
- ca65.exe <== the assembler from the cc65 package. Use this. The new version on the cc65 site crashes!
- ld65.exe <== linker from the cc65 package
- srec_cat.exe <== Converts bin file to .hex file
Output files
- osi_bas.bin <== the ROM fine in pure binary
- osi_bas.lst <== Assembly listing file
- rom.hex <== the ROM fine in standard INTEL-HEX format
To allow simple re-assembly, extract all files to the same folder
- Freeware utilities are available to convert the "bin" file to HEX or s19 (etc) - use your internet search tool to find
All source code, assembler binaries and the HEX dump of the ROM is here
- It is in standard INTEL-HEX format for uploading to a suitable programmer.
Having trouble running code

Programming References

6502 Instruction Set

Additional Tools

6502 Emulator - Simple emulator but it works
virtual 6502 / Emulator
6502.org Tools for the 6502
- Cross development package for 65(C)02 systems, including a powerful macro assembler, a C compiler, linker, librarian and several other tools

Mechanicals

Checkout

Rev 3

PCB Updates

Add bulk electrolytic cap
Make PH2OUT on VPB backplane line (swap wth VDA)
Change to vertical reset switch
Add an LED that is written by writing D0 to ROM area

Rev 2

Rev 2 Checkout

Install jumper J2:1-2 since CPU is R65C02
NOP tester - 6502 nop = 0xEA
- Works
Add LED
- 1.8K resistor from U2-17 to Ground
- Wire U2-11 to U1-33 CPUD0

Cut etch U1-39 in rear (removes PH2OUT from backplane)

Add wire U1-39 to J2-3 (PH2OUT/VPB on VPB output)

Rev 2 Changes

Add pull-up resistor on ABORT* line (U1-3)
Add pull-up resistor on BE line (U1-36)

Rev 1

Install jumper J2:1-2 if CPU is not a WDC 65C02 or WDC 65C816
If WDC 65C02 or WDC 65C816 is used:
- Add pull-up resistor on ABORT* line (U1-3)
- Add pull-up resistor on BE line (U1-36)

LB-65CXX-01

Contents

Features

Design

Memory Map

CPU

R65C02 vs W65C02 vs W65C816 CPUs

VDA/VPA (65C816)

Chip Set

Oscillator

PLD

PLD Listing

Reset Controller

Backplane connector

Software

Assembly Language Development Toolchain

ACIA Test Code

Simple Monitor 6502

6502 Enhanced BASIC

OSI BASIC

Programming References

6502 Instruction Set

Additional Tools

Mechanicals

Checkout

Rev 3

PCB Updates

Rev 2

Rev 2 Checkout

Rev 2 Changes

Rev 1

Assembly Sheet

Rev 2

Rev 1

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